There are vehicles in which various types of sensors, such as a yaw rate sensor, a steering angle sensor, and an acceleration sensor, are mounted. Errors contained in output values of such sensors (which will also be referred to as detected values) are preferably zero for use in various control operations.
Actually, the center value of a sensor output (i.e., a zero-point) is shifted from a design zero-point (i.e., zero) due to aging or temperature characteristics of the sensor or an initial deviation of the sensor output, thus resulting in an error of the detected value caused by the shift in the zero-point. In order to eliminate such a problem, various structures have been proposed which calculate an amount of deviation of the zero-point of the sensor and correct a detected value of the sensor using the calculated amount of the deviation.
For instance, Japanese Patent First Publication No. 2010-107244 discloses a structure which calculates a correction value corresponding to a deviation of the zero-point of an acceleration sensor using a detected value of the acceleration sensor in an interval between when a door of a vehicle is opened and when the door is closed, and uses an output of the acceleration sensor derived by subtracting the deviation of the zero-point from a detected value of the acceleration sensor.